Media recovery - Revision history

ELowell at 22:23, 28 September 2016

2016-09-28T22:23:29Z

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	[[Category:Model 204 files]]		[[Category:Model 204 files]]
			[[Category:Recovery]]

JAL: typo

2014-11-17T21:34:05Z

typo

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	Because some file discontinuities cannot be "crossed" by media recovery (that is, media recovery fails for the file if such a discontinuity appears between the file's starting and stopping points), take new file backups whenever one of these discontinuities is created. The list of actions that create these discontinuities appears in [[#File discontinuities\|File discontinuities]].</p>		Because some file discontinuities cannot be "crossed" by media recovery (that is, media recovery fails for the file if such a discontinuity appears between the file's starting and stopping points), take new file backups whenever one of these discontinuities is created. The list of actions that create these discontinuities appears in [[#File discontinuities\|File discontinuities]].</p>
	<p>		<p>
	Take new file backups whenever a file is updated by the <var class="product">Model 204</var> File Load ~~Utility~~ (FLOD and FILELOAD commands), or by IFAM1, because neither writes a log of file updates to the journal. For information about recovery under IFAM1, see the <var class="book">Rocket Model 204 Host Language Interface Programming Guide</var>.</p>		Take new file backups whenever a file is updated by the <var class="product">Model 204</var> File Load utility (FLOD and FILELOAD commands), or by IFAM1, because neither writes a log of file updates to the journal. For information about recovery under IFAM1, see the <var class="book">Rocket Model 204 Host Language Interface Programming Guide</var>.</p>
	<p>		<p>
	Media recovery cannot "cross" <var>RESTART</var> recovery discontinuities unless journals created by those recovery runs are included in CCAGEN. Archive journals created by recovery jobs just as you would any other updating job's journal.</p>		Media recovery cannot "cross" <var>RESTART</var> recovery discontinuities unless journals created by those recovery runs are included in CCAGEN. Archive journals created by recovery jobs just as you would any other updating job's journal.</p>

JAL: typo

2014-11-07T19:55:19Z

typo

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	Media recovery is the process of restoring a <var class="product">Model 204</var> file from a backup copy of that file, and then using the Roll Forward facility to reapply the updates that were made to the file since the time of the dump. These updates are obtained from the <var class="product">Model 204</var> journals written by all jobs in which updates were performed since the backup copy was made. The media recovery facility automatically performs Roll Forward and can (optionally) automatically perform the restoration; you do not need to invoke the RESTORE and RESTART commands. </p>		Media recovery is the process of restoring a <var class="product">Model 204</var> file from a backup copy of that file, and then using the Roll Forward facility to reapply the updates that were made to the file since the time of the dump. These updates are obtained from the <var class="product">Model 204</var> journals written by all jobs in which updates were performed since the backup copy was made. The media recovery facility automatically performs Roll Forward and can (optionally) automatically perform the restoration; you do not need to invoke the RESTORE and RESTART commands. </p>
	<p>		<p>
	[[System and media ~~Recovery~~]] describes the procedures to follow to recover entire databases in case of a system crash or some other system-wide problem. This page presents procedures for recovering individual files after a media failure such as a disk head crash. </p>		[[System and media recovery]] describes the procedures to follow to recover entire databases in case of a system crash or some other system-wide problem. This page presents procedures for recovering individual files after a media failure such as a disk head crash. </p>

	===Media recovery example===		===Media recovery example===

JAL: link repair

2014-10-28T18:38:47Z

link repair

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	Media recovery is the process of restoring a <var class="product">Model 204</var> file from a backup copy of that file, and then using the Roll Forward facility to reapply the updates that were made to the file since the time of the dump. These updates are obtained from the <var class="product">Model 204</var> journals written by all jobs in which updates were performed since the backup copy was made. The media recovery facility automatically performs Roll Forward and can (optionally) automatically perform the restoration; you do not need to invoke the RESTORE and RESTART commands. </p>		Media recovery is the process of restoring a <var class="product">Model 204</var> file from a backup copy of that file, and then using the Roll Forward facility to reapply the updates that were made to the file since the time of the dump. These updates are obtained from the <var class="product">Model 204</var> journals written by all jobs in which updates were performed since the backup copy was made. The media recovery facility automatically performs Roll Forward and can (optionally) automatically perform the restoration; you do not need to invoke the RESTORE and RESTART commands. </p>
	<p>		<p>
	~~The <var class="book">~~[~~http://docs.rocketsoftware.com/nxt/gateway.dll/RKBnew556/model%20204/v7.4/m204_v7r4_system_manager.pdf Rocket Model 204~~ System ~~Manager's Guide~~]~~</var>~~		[[System and media Recovery]] describes the procedures to follow to recover entire databases in case of a system crash or some other system-wide problem. This page presents procedures for recovering individual files after a media failure such as a disk head crash. </p>
	describes the procedures to follow to recover entire databases in case of a system crash or some other system-wide problem. This page presents procedures for recovering individual files after a media failure such as a disk head crash. </p>

	===Media recovery example===		===Media recovery example===
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	==Backing up Model 204 files==		==Backing up Model 204 files==
	<p>		<p>
	Because the success of media recovery depends upon the availability of backup copies of all <var class="product">Model 204</var> files, be sure to back up files on a regular basis. The <var class="product">Model 204</var> DUMP/RESTORE utility allows you to copy a <var class="product">Model 204</var> file to a sequential data set. The DUMP utility can be run either as a batch job, or in an Online while other users are accessing the file. See [[ File dumping and restoring#Using DUMP and RESTORE with media recovery\|Using DUMP and RESTORE with media recovery]] for a description of the DUMP/RESTORE utility. </p>		Because the success of media recovery depends upon the availability of backup copies of all <var class="product">Model 204</var> files, be sure to back up files on a regular basis. The <var class="product">Model 204</var> DUMP/RESTORE utility allows you to copy a <var class="product">Model 204</var> file to a sequential data set. The DUMP utility can be run either as a batch job, or in an Online while other users are accessing the file. See [[File dumping and restoring#Using DUMP and RESTORE with media recovery\|Using DUMP and RESTORE with media recovery]] for a description of the DUMP/RESTORE utility. </p>
	<p>		<p>
	Backups can also be taken using other DASD management software (such as FDR or DFDSS). However, if you need to back up a file while an Online that accesses it is still running, take the backup with the <var class="product">Model 204</var> DUMP command issued from the running Online. This ensures that the backup copy of the database is physically consistent.</p>		Backups can also be taken using other DASD management software (such as FDR or DFDSS). However, if you need to back up a file while an Online that accesses it is still running, take the backup with the <var class="product">Model 204</var> DUMP command issued from the running Online. This ensures that the backup copy of the database is physically consistent.</p>
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	==Producing and archiving journals==		==Producing and archiving journals==
	<p>		<p>
	The journal produced by a <var class="product">Model 204</var> run contains a record of file updates, as well as information about run characteristics, error messages, and utilization statistics. The journal data set (described in the		The journal produced by a <var class="product">Model 204</var> run contains a record of file updates, as well as information about run characteristics, error messages, and utilization statistics. The journal data set (described in [[Tracking system activity (CCAJRNL, CCAAUDIT, CCAJLOG)#Using the CCAJRNL data set\|Using the CCAJRNL data set]]) is vital to system and media recovery. </p>
	~~<var class="book">[http://docs.rocketsoftware.com/nxt/gateway.dll/RKBnew556/model%20204/v7.4/m204_v7r4_system_manager.pdf RocketModel 204 System Manager's Guide~~]~~</var>~~) is vital to system and media recovery. </p>
	<p>		<p>
	For a summary of statistics written to the journal, see [[ File statistics and tuning#File statistics summary\|File statistics summary]].</p>		For a summary of statistics written to the journal, see [[File statistics and tuning#File statistics summary\|File statistics summary]].</p>

	===Creating a journal===		===Creating a journal===
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	If you want to produce a journal for a run and use it in media recovery, the file manager or system manager must take the following actions for each job that updates the file:</p>		If you want to produce a journal for a run and use it in media recovery, the file manager or system manager must take the following actions for each job that updates the file:</p>
	<ul>		<ul>
	<li>Include a CCAJRNL data set or file definition statement in the JCL or EXEC for the run. (If multiple journal data sets are generated, additional data set definition statements can be specified.) See ~~the~~		<li>Include a CCAJRNL data set or file definition statement in the JCL or EXEC for the run. (If multiple journal data sets are generated, additional data set definition statements can be specified.) See [[Tracking system activity (CCAJRNL, CCAAUDIT, CCAJLOG)#Creating and generating CCAJRNL\|Creating and generating CCAJRNL]] for details. </li>
	~~<var class="book">Rocket Model 204 System Manager's Guide</var>~~ for details. </li>

	<li>Set the <var class="product">Model 204</var> SYSOPT (system options) parameter to include the 128 option (produce a journal or audit trail).</li>		<li>Set the <var class="product">Model 204</var> <var>SYSOPT</var> (system options) parameter to include the 128 option (produce a journal or audit trail).</li>

	<li>In the EXEC parameter or on User 0's parameter line, set the RCVOPT (recovery options) parameter to include the X'08' option (log Roll Forward information). </li>		<li>In the EXEC parameter or on User 0's parameter line, set the <var>RCVOPT</var> (recovery options) parameter to include the X'08' option (log Roll Forward information). </li>

	<li>During file creation or with the RESET command, set the FRCVOPT (file recovery options) parameter for each file to be regenerated. Ensure that FRCVOPT does not include the X'04' (suppress Roll Forward logging) option. </li>		<li>During file creation or with the <var>RESET</var> command, set the <var>FRCVOPT</var> (file recovery options) parameter for each file to be regenerated. Ensure that <var>FRCVOPT</var> does not include the X'04' (suppress Roll Forward logging) option. </li>
	</ul>		</ul>

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	<ul>		<ul>
	<li>Merge the journals together using the MERGEJ utility. Merging journals is discussed on [[#Merging journals\|Merging journals]].</li>		<li>Merge the journals together using the MERGEJ utility. Merging journals is discussed on [[#Merging journals\|Merging journals]].</li>
	<li>Write an EOF marker to any journal missing its EOF marker with the UTILJ utility. The UTILJ utility is described in detail in the ~~<var class="book">Rocket Model 204 System Manager's Guide</var>~~.</li>
			<li>Write an EOF marker to any journal missing its EOF marker with the UTILJ utility. The UTILJ utility is described in detail in [[System and media recovery#Using the UTILJ utility\|Using the UTILJ utility]].</li>
	</ul>		</ul>

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	<p>		<p>
	In addition to the standard STEPLIB, CCAIN, CCAAUDIT, and CCAPRINT data sets, the following data sets must be defined. Other data sets also might be needed as shown in the example.		In addition to the standard STEPLIB, CCAIN, CCAAUDIT, and CCAPRINT data sets, the following data sets must be defined. Other data sets also might be needed as shown in the example.
	These data sets are described in ~~the <var class="book">~~[~~http://docs.rocketsoftware.com/nxt/gateway.dll/RKBnew556/model%20204/v7.4/m204_v7r4_system_manager.pdf Rocket Model 204~~ System ~~Manager's Guide~~]~~</var>~~. </p>		These data sets are described in [[System and media recovery#Required data sets for media recovery\|Required data sets for media recovery]]. </p>
	<p class="note"><b>Note:</b>		<p class="note"><b>Note:</b>
	CHKPOINT data set is not required in a media recovery run.</p>		CHKPOINT data set is not required in a media recovery run.</p>
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	During media recovery, <var class="product">Model 204</var> verifies that the journal blocks in the input journal data set (CCAGEN) and that they are in chronological order. If a sequence error occurs, it indicates that the end of a journal was reached but that an EOF marker was not written. If a series of journals were concatenated, the UTILJ utility can be run to write an EOF marker on any journals that were not closed properly. Media recovery can then be rerun. </p>		During media recovery, <var class="product">Model 204</var> verifies that the journal blocks in the input journal data set (CCAGEN) and that they are in chronological order. If a sequence error occurs, it indicates that the end of a journal was reached but that an EOF marker was not written. If a series of journals were concatenated, the UTILJ utility can be run to write an EOF marker on any journals that were not closed properly. Media recovery can then be rerun. </p>
	<p>		<p>
	The UTILJ utility is described in the ~~<var class="book">Rocket Model 204 System Manager's Guide</var>~~. </p>		The UTILJ utility is described in [[System and media recovery#Using the UTILJ utility\|Using the UTILJ utility]]. </p>

	====Concatenation errors====		====Concatenation errors====

DmeWiccan: Automatically generated page update

2014-05-09T22:45:54Z

Automatically generated page update

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	</div> <!-- end div toclimit-3 -->		</div> <!-- end div toclimit-3 -->

	[[Category:~~File management~~]]		[[Category:Model 204 files]]

JAL at 21:41, 4 March 2014

2014-03-04T21:41:38Z

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JAL: more conversion cleanup

2014-03-04T20:54:31Z

more conversion cleanup

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ELowell: /* REGENERATE examples */

2014-02-11T21:41:02Z

REGENERATE examples

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	<li>Run REGENERATE with CCAGEN as either the weekly merged journal or the weekly merged journal with the same Thursday's Online journal concatenated or merged into it. </li>		<li>Run REGENERATE with CCAGEN as either the weekly merged journal or the weekly merged journal with the same Thursday's Online journal concatenated or merged into it. </li>
	<li><var class="product">Model 204</var> examines the database and finds the date and time of the last update unit. which completed before the backup was taken. This is the time that appears in the following message, when the file is opened with update privileges:</li>		<li><var class="product">Model 204</var> examines the database and finds the date and time of the last update unit. which completed before the backup was taken. This is the time that appears in the following message, when the file is opened with update privileges:</li>
	<~~/ol>~~		<p class="code">M204.1203: FILE WAS LAST UPDATED ON ...</p>
	<b>M204.1203: FILE WAS LAST UPDATED ON ...</b>
	~~<ol~~>
	<li><var class="product">Model 204</var> then scans the input journals (CCAGEN), and looks for the first update unit that began after this time. This becomes the "switch" that turns on the application of updates.</li>		<li><var class="product">Model 204</var> then scans the input journals (CCAGEN), and looks for the first update unit that began after this time. This becomes the "switch" that turns on the application of updates.</li>
	</ol>		</ol>
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	</p>		</p>
	<p><var class="product">Model 204</var> reapplies all updates that were part of update units completed before the time specified in this command.</p>		<p><var class="product">Model 204</var> reapplies all updates that were part of update units completed before the time specified in this command.</p>

	===Parameter settings===		===Parameter settings===
	<p>The following parameters must normally be set on User 0's parameter line for a media recovery job:</p>		<p>The following parameters must normally be set on User 0's parameter line for a media recovery job:</p>

ELowell: /* Media recovery using the REGENERATE command */

2014-02-11T21:38:02Z

Media recovery using the REGENERATE command

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	<p>This requires that the file backup have been taken with the <var class="product">Model 204</var> DUMP command. </p>		<p>This requires that the file backup have been taken with the <var class="product">Model 204</var> DUMP command. </p>
	==Media recovery using the REGENERATE command==		==Media recovery using the REGENERATE command==
	<p>You can use the REGENERATE command (abbreviation: REGEN) against a file that has been restored already to an earlier version in a separate job or job step.</p>		<p>You can use the <var>[[REGENERATE command\|REGENERATE]]</var> command (abbreviation: REGEN) against a file that has been restored already to an earlier version in a separate job or job step.</p>
	===REGEN without RESTORE===		===REGEN without RESTORE===
	<p>You can use the REGENERATE command without the RESTORE option to recover files that have been backed up with anything other than the <var class="product">Model 204</var> DUMP command.</p>		<p>You can use the REGENERATE command without the RESTORE option to recover files that have been backed up with anything other than the <var class="product">Model 204</var> DUMP command.</p>
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	<li>File was created prior to Release 9.0 of <var class="product">Model 204</var>. </li>		<li>File was created prior to Release 9.0 of <var class="product">Model 204</var>. </li>
	</ul>		</ul>

	==Running media recovery==		==Running media recovery==
	<p>A media recovery job regenerates files within a single-user (batch) <var class="product">Model 204</var> run. The job contains a <var class="product">Model 204</var> REGENERATE command, which specifies the name(s) of the file(s) to be regenerated. The syntax of the REGENERATE command is shown In the <var class="product">Model 204</var> Parameter and Command Reference.</p>		<p>A media recovery job regenerates files within a single-user (batch) <var class="product">Model 204</var> run. The job contains a <var class="product">Model 204</var> REGENERATE command, which specifies the name(s) of the file(s) to be regenerated. The syntax of the REGENERATE command is shown In the <var class="product">Model 204</var> Parameter and Command Reference.</p>

JAL at 20:40, 17 January 2014

2014-01-17T20:40:34Z

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	<li>Installing the MERGEJ utility, which is used to merge into a single file the journals produced by different <var class="product">Model 204</var> runs. This task is described in the Rocket <var class="product">Model 204</var> installation guide for your operating system. </li>		<li>Installing the MERGEJ utility, which is used to merge into a single file the journals produced by different <var class="product">Model 204</var> runs. This task is described in the Rocket <var class="product">Model 204</var> installation guide for your operating system. </li>
	<li>Dumping <var class="product">Model 204</var> files on a regular basis. This can be done either with the DUMP command, described in [[File dumping and restoring]], or with any standard DASD management software such as FDR. The installation must establish procedures for backing up all <var class="product">Model 204</var> files periodically, so that backups are available for recovery runs. </li>		<li>Dumping <var class="product">Model 204</var> files on a regular basis. This can be done either with the DUMP command, described in [[File dumping and restoring]], or with any standard DASD management software such as FDR. The installation must establish procedures for backing up all <var class="product">Model 204</var> files periodically, so that backups are available for recovery runs. </li>
	<li>Producing and archiving journals from all <var class="product">Model 204</var> update runs. If journaling is active for a run, <var class="product">Model 204</var> writes to the journal data set all updates made to the file during the run. <var class="product">Model 204</var> also logs such events as checkpoints, discontinuities, and other run information. ~~</li>~~		<li>Producing and archiving journals from all <var class="product">Model 204</var> update runs. If journaling is active for a run, <var class="product">Model 204</var> writes to the journal data set all updates made to the file during the run. <var class="product">Model 204</var> also logs such events as checkpoints, discontinuities, and other run information.
	<~~/ul~~>		<p class="note"><b>Note</b>
	<b>Note</b>		If media recovery is to be run, an installation must maintain journals containing a complete record of update activity, in all kinds of runs - Online, batch, and recovery. </p>
	~~<p>~~If media recovery is to be run, an installation must maintain journals containing a complete record of update activity, in all kinds of runs - Online, batch, and recovery. </p>		</li>
	<ul>
	<li>Running the MERGEJ utility to merge together any overlapping journals needed for a media recovery run.</li>		<li>Running the MERGEJ utility to merge together any overlapping journals needed for a media recovery run.</li>
	<li>Creating the file, if it has to be moved to a different physical location. </li>		<li>Creating the file, if it has to be moved to a different physical location. </li>